In the Lucifer episode "Love Handles" (S02E12), Lucifer and Chloe investigate a mysterious masked killer who is poisoning college students. They also try to make sense of their new relationship after a long-awaited kiss.

Up to this point it is very clear what is happening, perhaps at the end of the episode Lucifer and Chloe kissed each other and that is completely normal and long awaited by all of us.

Chloe was not a victim of the mad scientist like the others, nor did she have contact with the poison solution, only with the antidote.

She also witnessed the suicide of the scientist but had no contact with him.

What caused this bleeding? What's even more confusing is that her bleeding is very similar to the symptoms of the poison the scientist used.

I think it's clear that Chloe has been exposed to the poison, given the similarity in the symptoms between her and the other victim. It also makes sense within the plot -- she's going to die without an antidote that no one knows how to make. (Presumably it will require divine intervention to save her.)

Obviously, she did come into contact with the poison, at some point. We still don't know exactly how the poison is transmitted. We know that just skin contact is enough to contract it, as the drug dealer died that way.

Given that the scientist was expecting them to show up, there are any number of places in his lab he could have laced with the poison, or he could have exposed her to it somehow during the chase, or at the end.

At this point, my confusion is about the kiss, it doesn't have nothing related with it? Lucifer was inside the lab while Chloe ran out following the mad scientist. Feel free to edit your answer.
– Richard AlonsoJan 30 '17 at 20:37

I don't think the kiss has anything to do with Chloe getting poisoned; we may learn more in the next episode.
– KutuluMikeJan 31 '17 at 1:06